A driver who was stopped last year by Harlem cops for making a wrong turn mentioned “a body” in Mamaroneck that led them to the corpse of a woman he’s accused of killing, the Westchester district attorney said yesterday.

The DA’s statement came after Reginald Powell, 55, pleaded not guilty in White Plains court to killing Jennifer Katz, 49, and other charges.

When pulled over while driving Katz’s car last Dec. 30, Powell “made reference to a body” that pointed cops to Katz’s body in a closet in her home, DA spokesman Lucian Chalfen said.

Prosecutor Tim Ward said Powell was the brother of a man Katz had lived with for two years.

Powell was paroled in 2008 after serving 24 years for a 1982 killing, authorities said.